downslanting palpebral fissures

This is primarily a skeletal disorder with impaired skull ossification and multiple bone fractures of prenatal origin.  It is sometimes confused with forms of osteogenesis imperfecta.  The skull is poorly ossified and frequent diaphyseal fractures of the long bones occur leading to motor delays and short stature.  Rib fractures are sometimes seen. Intelligence seems to be normal.  A receding chin has been noted and the hard palate is highly vaulted.  The midface is flat.

Pregnancies may be complicated by polyhydramnios.  Infants are born with craniosynostosis with a cloverleaf pattern usually.  The skull is often shortened in the anteroposterior axis with flattening of the occipital region.  The skin is deeply furrowed with the cutis gyrata patterns most prominent in the posterior scalp but also present on the palms, soles, pinnae, and elsewhere.  Acanthosis nigricans is often present.

There is midface hypoplasia and nearly all individuals have intellectual disability.

The external ear canals can be atretic, the nares are often anteverted, and the mouth may be small.  An excess number of neonatal teeth and hypoplastic nails have been noted.  Hydrocephalus is common.  The umbilical stump is often unusually prominent.  Anogenital anomalies such as an anteriorly placed anus, cryptorchidism, and bifid scrotum may be present.  Pyloric stenosis is sometimes present.

Upper airway obstruction with respiratory distress may necessitate a tracheotomy. A cartilaginous tracheal sleeve replacing the normal C rings of cartilage has been found in several infants. These can be difficult to detect and their presence may have been responsible for breathing restrictions that has led to the demise of some children before two years of age.